Telephone-exchange system



H. CLAUSEN AND C. I.. GUODRUIVI.

TELEPHONE EXCHANGE-SYSTEM.

APPLICATION FILED D'EC. 28, H218.

Char/es 600m/w71.

H. P. CLAUSEN AND L. GOODRUIVI.

TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED DEC. 28, 1918.

2 SHEETS-SHEET 2.

Conneco l fL v HENRY l?. CLUSEN, l'? MCO'NT VERNON, AND CHARLES L.GOODR-ULJI, OF NEW YORK, N. Y., ASSIGNORS TO WESTERN ELECTRIC COMPANY,NCORPORATED, OF N11-lijf YORK, N. Y., A CORPOR-.LTION 01u" NEN YORK.

TELEHONE-EXCHANGE SYSTEM.

Maaate.

Spec Fioaton. ci" Letters I'atent.

1Patented Aug. 22, 1922.

Application filed December 28, 1918. Serial No. 268,665.

T0 all wim/m t 'may concern.'

Be it lrnown that we, HENRY P. CLAUsnN and @Hannes L. GoonnUM, citizensof the United States, residing at Mount Vernon, in the county otWestchester and State of N ew York, and at New Yorlr, in the county ofNew York and State of New York, respectively, have invented certain newand useful Improvements in Telephone-Exchange Systems, of which thefollowing is a full, clear, concise, and eXact description.

rlhis invention relates to improvements in telephone exchange systemsand has particular reference to an improved arrangement for controllingthe operation of selectively operable switching devices employed inmachine switching systems.

in automatic systems, false setting oit switches is often due to thecalling subscriber operating his impulse sending device before a trunkhas been seized leading to a selector switch designed to receive saidimpulses. This results in the switch being incorrectly set and a wrongnumber called..

An object of this invention is to avoid the calling of a wrong number bypreventing` the operation or' a switch should a subscriber manipulatehis impulse sending device before the circuit, over which the impulsesare to be transmitted to said switch, is complete. In accordance withthis object, each selector switch is provided with means which remainseffective while the switch is in normal position, but which is renderedineiiective upon the first step of the switch under certain conditions.Another means preferably similar to that at the selectors is placed atthe sending device and remains inactive until said device is actuated.rlhe line relays of the selector switches are adjusted to operate whenone of said means is effective but will not energize whenA both aresimultaneously effective. Therefore, should the subscriber operate hisdial before a'trunk leading to a selector switch which has been seized.the means at the sending device is made effective, and upon seizure ofsaid trunk, the means at said switch will also be rendered effectivewith the result that the line relay of the switch will not energize, theset of impulses Jtrom the sending device will be lost and a connectionwill not be established with a terminal leading to a called line.

The inventive idea involved is capable of receiving a variety ofexpressions one of which, for the purpose of illustrating theinvention,` is shown in the accompanying drawings; but it is to beexpressly under- -stood that said drawings are employed merely for thepurpose of facilitating the de# scription of the invention as a wholeand not to dene the limits thereof, reference being` had to the appendedclaims for this purpose.

1n the drawings, Fig 1 is a diagrammatic illustration of a callingsubstation, a line finder and a selector switch. Fig. 2 illustratesdiagrammatically a connector switch and a called substation.

lt is believed that the invention will be best understood 'from adetailed description of the operation in establishing a connectionbetween a` calling and a called substation. The subscriber at substationA, by removing` his receiver from its switchhook, completes a circuitfor line relay 100 of the line finder B extending from grounded battery,left winding of relay 100, outer armature and.

back contact of cut-ofi' relay 101, substation apparatus A, impulsesending device C, conductor 102, contacts 103, conductor 104, backcontact and inner armature of relay 101 and right winding of relay 100to ground. The energization of relay 100 completes a circuit fromgrounded battery, lett winding of said relay, outer armature and backcontact of relay 101, conductor 105, contact spring 106, back contactand lett armature ot relay 1.07, and. winding .of relay 10S to ground.Relay 108, by attracting its left-hand armature completes a lockingcircuit for itself, which is independent of the leit armature and baclrcontact of relay 107. ln attracting its right armature, relay 108completes a circuit from grounded battery, winding oi slow-to-releaserelay 109, right armature and front contact ot relay 108 to ground.Relay 109, by attracting its right armature, completes a circuit forrelay 107 extending from grounded battery, winding of relay 107, rightarmature and front contact oft relay109 to ground. Relay 107 lenergizesand at its right-hand" :armature maintains the release circuit of theline linder B open during the operation of this switch. Relay 109 at itsleft armature completes a circuit 'from grounded battery, winding ofprimary stepping magnet 110, sideswitch wiper 111 in its first position,back contact and armature of secondary stepping magnet 112, armature andback contact oit' magnet 110,v armature and back Vcontact ot' releasemagnet 113, side-switch wiper 114 in its first position, lett armatureand trent contact of relay 109, right armature .and front contact ofrelay 108 to ground. Primary magnet 110 interrupts its own circuit andcontinues to operate until the wiper 115V engages the contact 116associated with the group ofvlines containing the calling subscribersAline.'l then so engaged, a ground will be found on said contact whichycompletes a circuit from grounded battery, 'winding of primary magnet110, winding ot escape magnet 117, side-switch wiper 118 in its firstposition, wiper 115, contact 116, right armature and trent contact etrelay 108 to ground. Primary magnet 110 is maintained energized'by thecurrent vflowing fthrough this circuit, thereby preventing further stepning of the switch in the primary direction. scape magnet 117 is alsoenergized `by this circuit and upon its energization moves. theside-switch wipers into their second positions. In this position,primary magnet 110 and escape magnet 117 are. maintained energized overva vcircuit extending from grounded battery, winding of primary magnetl110, winding vof escape magnet 117, side-switch wiper 118 in' position2, sideswitch wiper 114 in position 2, 'lett-hand armature and frontcontact of relay 109, right-hand armaturev andtront contact ot relay 108to ground. A circuit is new closed for the secondary stepping magnet 112extending from grounded battery, winding ot magnet 112, side-switchwiper 111 in its second position, baclcontact and armature ot magnet112, right armature and trent contact of escape` magnet 117, rightarmature and back contact 'ot' release magnet 113, sideswitch wiper 114-in its second position, lett armature and front contact of relay 109,right armature and iront contact oit relay 108 to ground. This steppingcircuit ttor the secondary magnet 112 is maintained until. th c brushes119, 120 and 121 oit the line linder B engage the terminals 122, 123,124- oit the calling subscribers line. When so engaged, a circuit iscompleted i'or cut-ott relay 101, extending trom'grounded battery,wind--A 'ing ot relay 101, terminal 122, brush 119, lett armature ofescape magnet 117, resistance 127, side switch wiper 114, left-handarmature and front contact ot relay 109, right-` hand armature andliront contact ot relay 108 to ground. Relay 101 energizes and breaksthe locking circuit tor relay 108 at the outer armature and back contactot said relay 101. Relay 108 releases and'opens the circuit for escapemagnet 117 which deenergizes and moves the side-switch wipers lintoposition 3, lCut-oitrelay 101 remains enermessie gized in this positionot the side switch over a circuit extending from grounded battery,winding of relay 101, terminal 122, brush 119, contact spring-125,contact 126, left armature and back contact oli release magnet 113 toground.

Assuming that the subscriber at the substation A had not operated theimpulse senading device C previous to the movement ot the side-switchwipers ot the line iinder switch B to their third positions, themovement of the `wipers 128 and 129 to `such position willl extendthecalling subscribers line to the first selectorl switch D, atA which timea circuit will be'closed tor line relay 200 of saidselector switchextending from grounded battery, lett winding ot relay 200, resistance201, side-switch wiper-202 in *position 1, the lower side` ot thetelephon'elin'e, substation apparatus A, sending device C, conductor102, contacts 103, conductor 104, upper side of the telephone line,side-switch wiper 203, and right winding otl relay 200 to ground;

Howevem'should the subscriber at substation A manipulate the'dial ot thesending device C previous'to the movement ot wipers 128 and 129- toposition 3, contacts 103 at said sending device will be opened and theresistance 130 included in the subscribers line. Relay 100 will,however, continue to be energized and the line finder switch willoperate to connect the calling line with selector switch l), atwhichtime the two resistances 130 and 201will be inl series. v Relay 200is so adjusted that the same will not energize when these resistancesare in series and consequently the selector switch will tfail to respondto impulses transmitted from the sending device C. It will, therefore,be apparent that the set ot impulses designed toA operate thesel'ectorcswitch D will be lost and succeeding impulses for operatingthe other switches will. tail to establish a conneetion to terminalsleading to the called line.

New, assuming again' that the sending device at substation A wasproperly operated and` that relay 200 ot the selector switch l) becameenergized upon movement ot the side-switch wipers-128', 129 to position8,V energiaation et relay 200 will close a` circuit for slow-to-releaserelay 204I eX- tending trom grounded battery, winding ot relay 2011,trent contact and armature ot relay 200 to ground, and relay 204e willbecome energized. t is to be noted that during the operation oi thesending device, resistance 180 will be included in the circuit withresistance 201 until switchl D is stepped from normal but relay 200 isso adjusted that thc same will not release when said resistances are inseries. The switch is now in position to receive the first series otimpulsesA transmitted from the sending device at substation A and invresponse .to each impulse, line relay200 will bel momentarilydeenergized. Upon each deenergization, a circuit willbe closed fromgrounded battery, winding of primary stepping magnet 205, contact 206,front contact and armature of relay 2011, back contact and armature ofrelay 200 to ground. Thelirst deenergization of line relay 200 and thecon-v sequent st'epping of the switch by the operation of magnet 205,will close the off-normal contact 216 and thus provide a shunt for theresistance 201, which will permit energization of relay 200, since onlythe resistance 180 is now included inthe line circuit, while the sendingdevice C is `operated. A circuit is also completed for slowto-releaserelay 207 extending from grounded battery, winding of relay 207,front'contact and armature of relay 204, back contact and armatureofrelay 200 to ground. Energization of relay 207 completes a'circuitfrom grounded battery, winding of escape magnet 208, side-switch wiper209 in position 1, armature and front contact of vrelay 207 to ground.Relays 204 and 207 being slow to release, will maintain their armaturesattracted during the transmission of impulses to relay 200. At thetermination of the first series of impulses, relay 200 lremainsenergized for a suliicient length of time to permit deenergization ofrelay 207 and upon its release, escape magnet 208 will deenergize andvmove the side-switch wipers into position 2. In this position, a circuitwill be closed for secondary `stepping magnet 210 extending fromgrounded battery, winding of' said magnet, armature and back contactthereof, side-switch wiper 211 in position 2, front contact andarmatureofrelay 200 to ground. klt/iagnet 210, being self-interrupting,will'step brushes 212, 213 and 214@ over the terminals ofthe selectedgroup until an idle trunkleading to the connector switch E is found, theidle condition of this switch being denoted by a ground upon the testterminal 215.l As

soon as brush 212 engages terminal 215, a circuit will be closed forescape magnet 208 extending from grounded battery, winding of saidmagnet, side-switch wiper 209 in position 2, brush 212, terminal 215,left armature and back contact of relay 300 of the connector switch,back contact and right armature of slow-to-releaserelay 301, backcontact and armature of linerelay SO2-to ground. Escape magnet 208energizespand nieves the side-switch wipers of the selector switch Dinto position 3.

it the subscriber at substation A'sliould operate his sending deviceprevious to the seizure of the trunk leading to connector switch E,contacts 103 will again be opened and resistance 130 included inthe linecircuit. Upon movement of the side-switch winding of said relay, frontcontact and vseries with resistance 130 and said line relay will fail'toenergize, with the result that the secondsetof impulses intended to stepthe connector switch. ,will bel lost and saidswitch will remain inits-normal position. r f.-

ssuming that the operator at substation A did not: operate his sending`device before the trunk leading to connector switch E wasy seized, themovement ofV side-switch wipers 202 and203 into position y3 will extendthe line to said connector-switch. A circuit is then` completed "fromgrounded battery, `right winding of line relay 802,

lower side ofthe telephone line, substation apparatus A, 1 conductor'102,-' contactsy '103,

conductor 1041, upper side of the telephoney line, resistance 430S andleft winding of relay 302 to ground. Energization of relay 302 closes acircuit `for slowto-release relay eXtending from grounded battery,

armature of relay 302to ground.' The con- -nector switch is now incondition to receive:

the 'second' series o'f impulses. After the dial of sending device C hasbeeninitially adjusted but ybefore the first impulse isA trasmitted,resistances 130 and 303 are in series, but relay 302 is adjusted so thatthe same will not release when 'this condition exists. A i

In response toeach impulse of this series,`

linerelay 302 is momentarily deenergized and thereby completes lacircuit for primary stepping magnet 30-14 extending from groundedbattery, winding of said magnet,

side-switch wiper 305 in position 1, front contact and right armature ofrelay 301, back contact and armature of relay 302 to ground. A circuitis also completed for 'slow-to-releas'e relay 306 extending fromgrounded battery, winding of said relay,v

front contact and right armature of relay 301, back contact and armatureof relay 302 to ground. Relays 301 and 306 being'slowto-release,`w`illbe maintained energized durv ing the transmission of the setofiinpulses.

Energization of relay 306 establishes a lcircuit'eXtending-from groundedbattery, front contact yand right varmature of relay 306,

winding of escape magnet 307, back contact and armature `of marginalrelay 308 to ground. Upon the lirststep of theconnector switch,olf-'normal contacts 309 `and 310 will close and the latter contact willvshunt thek resistance 303 so that the same will not bein serieswiththe'resistance 130 at sub` termination of the impulses, line relay302 stepping will remain energized, thereby causing 4the deenergizationof slow-.to-release relay 306. Release of relay 306 will open thecircuit for escape magnet 307, which, upon releasing, will move theside-switch wipers of the connector switch intoposition 2'. y

The third set of impulses will again vibrate the armature of line relay302 and cause energization of relays 301 and 306 and escape. magnet 307,as previously described. A circuit is also closedfor the secondary`magnet 311 extending from grounded battery, winding of magnet 311,side-switch wiper 305l i-n position`2, front contact and right armatureoi? relay 301, back- Contact and armature of relay 302 to ground.Secondarymagnet 311 operates to step the brushes 312, 313 and 314 on tothe terminals 315, 316 and 317 individual to the telephonelineassociated with the called substation F.4 Should the called line bebusy, aground will be found upon test terminal 315. It thisline. is busyas a calledl line, this ground will be connected through sideswitchwiper` 318 in position 4 and` brush 312 of some other connecting switch,or if busy as a calling line, ground will be connected throughthe leftarmature and back contactotI release magnet 113, make-beforebreakcontact 126, contactspring 125, and brush 119- of a line iinder Bconnected thereto. Therefore, when relayI 306 deenergi'zes after thethird series of impulses, a circuit will be completed for release magnet321, whichv maybe traced' from groundedl battery,v right winding ofrelease magnet 321,

4right armature and back contact of relay 300, off-normal contact 309,left armature and back contacty of relay 306, side-switch wiper 318,brush 312 and lterminal 315l to ground.- Release magnet 321 establishesa holding circuit for itself extending from grounded battery, winding ofrelease `magnet 217, off-normal contact 218 which was' closed upon theiirst step of the selector v switch D, side-switch wiper 219 in position3, brush 212, terminal 215, left armature and front contact of relay 301liront contact and f lett armature of magnet 321 and left winding oi'said magnet to ground. Since escape magnet307l is made slow to release,the circircuit for release magnet 321 energizes release. magnet 217 0fSelector switch D`r and causes this switch to return to normal, at whichtime the 05E-normal contact 218 will be opened. Acircuit is alsoyestablished in parallel with magnet21'7 extending from grounded battery,winding of release magnet 113 of line finder B, off-normal contacts 131,armature and back contact of relay 107, `side-'switch wiper 219 inposition 3, brush 212, terminal 215, left armature and front contactofIrelay 301, frontlconta'ct and left armature of release magnet 321, andleft winding of said magnet to ground. Energization of the. releasemagnet 1131 returns the` line finder switch D to normal position in amanner well' known in the art. li the called line Vleading to substationF had been idle. at lthe tiinef the brush 312 engaged terminal- 3-15, noground would have been found on said terminal so that deenergi'zationoff relay 306 would haved caused the release oit-'escape magnet 307 andthe sideswitch wipers of the connector switch would have been moved intoposition 3.

In position 3, a circuit is completed from grounded battery, winding of'relay 3.06,

side-switch. wiper 305, in position 3, front contactand armature ofrelay 302 to ground.

Rela v 306 enero'izes and again establishes y b a the energizing circuitfor escape magnet 307,

which in attracting its armature,'completes a circuit from a ringinggenerator (not shown), front contact and armature of escape magnet- 307,winding of marginal relay 308, side-switch wiper 319 Vin position 3,brushv 313, terminali 316', apparatus at. sublOO station F, terminal317, brushl 314, sideswitch wiper 320 inposition 3, front contact andarmature of relay 302 to ground.

The current flowing through this circuit is not suiiicient to `operatemarginal relay'308 at this Jtime, but as soon as the subscriber atsubstation F removes his receiver kfrom its switchhook, therebyshuntingtlie ringer at this substation, suiiicicnt 'current flowsthroughy the marginal relay 308` to cause itf to attractits varmatureand open the circuit of escape magnet 307. This escape magnetdeenergizes and. moves the" side-switch wipers into position 4.

A. connect-ion'has nowbeen established between substations A. and F, andtalking current is; supplied; to thecalled .subscribers line fromgrounded battery', le'lt windingv oit relay- 300, side-,switch wiper319, brush 313, terminal 316, substation apparatus F, terminal 317,vbrush 3'14, side switch wiper 320 and right winding of relay300 toground'.

At the termination of conversa-tion the subscribers at substations A andF will, by replacing their receivers, deenergize line re` lays 300 and302.y VRelease. ofV relay 302 causes in turn'the deenergization ofslow-torelease relay 301. Ground is then` connected toV theV releaseconductor 323 through the varmature. and back Contact. of relay 302,

CII

right armature and baclr contacto't relay 301, back contact and leftarmature ot relay 30G. 'Circuits :tor release magnets i123, 217 and 321are then completed over the conductor 323 and the respective switchesassociated with these release magnets will be returned to normal, aspreviously referred to.

V7 hat is claimed is:

l. lln an automatic telephone exchange system, a calling subscribersline, an impulse sending device thereat, means tor eX- tending saidcalling subscribers line, a switch for connecting said callingsubscribers line with the last named means and resistances at saidsending device and said eX- tending means operable to prevent actuationof the latter it said extending means is connected to the sending devicewhile said sending device is operating.

2. ln an automatic telephone exchange system, a calling subscribersline, an impulse sending device thereat, means for extending saidcalling subscribers line, a switch for connecting said callingsubscribers line with the last named means, variably adjustable meansfor operating said sending device to control the operation of said er:-tending means and resistances at said sending device and said extendingmeans operaable to prevent actuation of the latter it said extendingmeans is connected to the sending device while said sending device isoperating.

3. ln a telephone system, a telephone line, asender therefor, anumerical switch, means :for automatically extending saidline to saidswitch upon the initiation ot a call therein, and means for preventingsaid numerical switch from responding to the first set ot impulses fromsaid sender, said means being rendered effective only in case saidnumerical switch is connected to the sender while the sender isoperating.

4l. ln a telephone system, a telephone line,

-a dial therefor, a numerical switch, means for automatically extendingsaid line to said switch upon the initiation ot a call therein, andmeans r'for preventing said numerical switch from responding to thefirst set of impulses from said dial, said means being renderedeltective only in case said numerical switch is connected to said dialwhile the dial is operating.

5. ln a telephone system, a telephone line, a sender therefor, anumerical switch, a progressively movable non-numerical switch forautomatically extending said line to said numerical switch upon theinitiation of a call in said line, and means 'for preventing saidnumerical switch from responding to the first set of impulses from saidsender,

said means being rendered effective only in case said numerical switchis connemed to said sender while the sender is operating.

6. ln a telephone system, a subscribers line, a dial thereat, aselector, an automatic iinder switch for extending said line to saidselector upon the initiation ot a call, and means rendered effective incase the selector is connected to the dial while the dial is oft".-normal :tor preventing the corresponding set of impulses from affectingthe selector.

7. ln a telephone system, a telephone line, a selector, groups of trunksterminating in numerical switches, a sender associated with said line,said selector being controlled by the initial set of impulsestransmitted by said sender to select a grounp of trunks, means forcausing said selector to select an idle trunk in said selected group,and means 'for preventing the numerical switch in which said idle trunkterminates from responding to the succeeding set ot impulses, said meansbeing rendered eective in case said telephone line is extended to thesaid numerical switch while said sender is operating.

8. ln an automatic telephone exchange system, a calling subscribersline, an impulse sending device, a selector switch, for extending saidline, an impulse relay for said selector switch, a switch torinterconnecting said calling subscribers line with said selector switchand resistances operable to prevent actuation of said relay in responseto the first set of impulses from said sending device, said resistancesbeing rendered effective only in case said selector switch is connectedto said sending device while the Sending device is operating.

9. In an automatic telephone exchange system, a calling subscrihersline, a sending device, a selector switch for extending said line, animpulse relay for said selector switch, a switch for interconnectingsaid calling subscribers line with said selector switch, variableadjustable means for operating said sending device to control the op--eration of said selector switch and resist-l ances associated with saidsending device and said selector switch to prevent actua tion of saidrelay in response to the first set ot impulses from said sending device7said resistance being rendered effective only in case said selectorswitch is connected to said sending device while the sending device isoperating. n

ln witness whereof, we hereunto suhscribe our names this 12th day ofDecember a. D., 1918. i

HENRY r. cnausniv.

oiiannns L. GooDnUa/r.

